铺设铁路的钢轨所用的合金钢中含有( )
A.钨
B.硅
C.锰
D.铬和镍
锰钢的主要成分是铁、锰、碳,其韧性好,硬度大,主要用于钢轨、挖掘机铲斗、坦克装甲、自行车架.
故选C
We will be at 10 Baker Street at six o’clock, and we ______ seeing you there.
A.look out for
B.look for
C.look forward to
D.look down upon
揉膻中穴治疗痰吐不利时,常同揉天突和()合用
A.揉足三里
B.摩腹
C.揉脐
D.揉丰隆